JP3531597B2 - Organic electroluminescent device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an organic electroluminescent device that can be used in the fields of display devices, flat panel displays, backlights, interiors, etc., and a method for manufacturing the same.

[0002]

2. Description of the Related Art Plasma displays (PDPs) and electroluminescence displays (ELDs) have been attracting attention as light emitting flat panel displays. In particular, organic electroluminescence devices have high brightness and are capable of full color display research and development. Is thriving.

These flat panel displays are display devices for converting image information electric signals into image light. The dot matrix type, which is an example for realizing this, is roughly classified into a simple matrix type and an active matrix type. The simple matrix type is composed of opposing striped electrodes arranged to intersect each other, and a time division method such as a line sequential driving method is adopted. In the active matrix type, an electric switching means is attached to the inner surface of the electrode substrate on one side. A thin film transistor (TFT) circuit is generally used as the switching means.

The organic electroluminescence device emits light by recombining holes injected from the anode and electrons injected from the cathode in the organic light emitting layer sandwiched between the both electrodes. The typical structure is that a transparent first electrode (anode), a hole transport layer, an organic light emitting layer, and a second electrode (cathode) are laminated on a glass substrate. It is taken out through the electrode and the glass substrate.

Each of the light emitting regions of the organic electroluminescent device is a portion where the first electrode and the second electrode, which are opposed to each other, intersect and overlap each other. In the case of a color display, one pixel is formed by three individual light emitting regions emitting red, green and blue light. Since the brightness and color balance of the display are designed on the assumption that these light emitting areas emit light uniformly, an insulating layer is formed on the overlapping portion of the first electrode and the second electrode or on the first electrode. In some cases, it is necessary that the part of the range regulated by it emits light.

[0006]

However, the area of the actual light emitting area that actually emits light is larger than the area of the light emitting area defined by the first electrode and the insulating layer and the second electrode provided thereon. Is small, that is, there is a case where the light emitting region as designed cannot be obtained. The part that does not emit light often occurs in the peripheral part of the light-emissible region. Therefore, at the same time as the area of the light-emitting region is reduced, the shape of the light-emitting region is not the designed sharp shape but the outer shape is blurred. As a result, uneven brightness occurs, display characteristics deteriorate, or brightness decreases when the same voltage is applied. Furthermore, the area of the actual light emitting region tends to decrease with time, and it is more difficult to suppress this phenomenon for a long time.

[0007]

In the organic electroluminescent device of the present invention, the area of the light-emissible region defined by the first electrode, the insulating layer provided thereon, and the second electrode is 1 square.
The substrate is 80 mm or less before forming the thin film layer.
By dehydrating the insulating layer by heating above
According to another aspect of the present invention, there is provided an organic electroluminescent device, wherein an effective light emission rate defined as a ratio of an area of the light-emissive region to an area of an actual light-emission region that actually emits light is at least 80% or more. In addition, another organic electroluminescent device of the present invention
Is the first electrode and the insulating layer and second electrode
The area of the light-emissible area defined by the poles is 1 square
It is less than 1 meter and the substrate is depressurized in a decompressed atmosphere before forming the thin film layer.
Dehydrate the insulation layer by leaving it under the air for 10 minutes or more
Causes the area of the light emitting region to actually emit light.
Effective emission rate defined as the ratio to the area of the actual emission area
Is at least 80% or more
It is a field light emitting device.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The organic electroluminescence device of the present invention is formed on a first electrode, an insulating layer formed so as to cover a part of the first electrode, and formed on the first electrode. And a second electrode formed on the thin film layer including a light emitting layer made of at least an organic compound. The manufacturing method includes a step of forming an insulating layer so as to cover a part of the first electrode formed on the substrate, and a step of forming a thin film layer including at least a light emitting layer made of an organic compound on the first electrode. And a step of forming a second electrode on the thin film layer.

The light-emissible area of each light-emitting pixel is defined by the first electrode, the insulating layer, and the second electrode. In a simple matrix type display, the first electrode and the second electrode are formed in a stripe shape and intersect each other, and the insulating layer is formed so as to have an opening smaller than the intersecting portion, so that it can emit light. The area is often rectangular. In the active matrix type display, the part where the switching means is formed may be arranged so as to occupy a part of the light emitting region, and the shape of the light emitting region is not a rectangular shape but a partly lacking shape. Often becomes. However, the shape of the light-emissive region is not limited to these, and may be circular, for example, and can be easily deformed depending on the shape of the opening of the insulating layer.

In the present invention, the ratio of the area of the actual light emitting region that is actually emitting light to the area of the light emitting region is defined and used as the effective light emission rate. As for the boundary between non-light emission and light emission, a portion where the luminance is 50% or less compared to the luminance of the normal portion is set as a non-light emission area. When the light-emissible region emits light over the entire surface, the effective light emission rate is 100%. However,
In reality, it was always difficult to achieve this.

The cause of such a non-luminous region is
It is considered that the water adsorbed on the surface of the first electrode or the insulating layer diffuses into the inside of the device after the device is manufactured and inhibits light emission. Due to such a cause, the peripheral portion of the light emitting region, which initially emits light, does not emit light, and the effective light emission rate decreases.

The organic electroluminescent device of the present invention has an effective light emission rate of 80% or more. If the effective light emission rate is 80% or more,
The brightness variation and the like accompanying it is suppressed to 20% or less, which is preferable, and in order to obtain higher display quality, the effective light emission rate is preferably 90% or more, and more preferably 95% or more.

It is a common phenomenon that the effective light emission rate decreases with time even if the effective light emission rate is high immediately after the fabrication of the organic electroluminescent device. For display applications, it is preferable to maintain a high value of the effective light emission rate for at least 5 years, but such measurement of the effective light emission rate over a long period of time is not practical. Since the effective luminescence rate greatly decreases immediately after fabrication, it is possible to predict the subsequent decrease in the effective luminescence rate by measuring the initial change. A criterion for sufficiently suppressing the phenomenon over time is that the effective light emission rate after 7 days, more preferably after 1 month, and still more preferably after 3 months is 85% or more. .

Taking the case of a simple matrix display as an example, FIGS. 1 and 2 show the light emitting region and the actual light emitting region in the present invention. FIG. 1 is a plan view showing a light emitting region and an actual light emitting region, and shows a light emitting region 15 and an actual light emitting region 16 defined by the ITO first electrode 2, the second electrode 8 and the insulating layer 4. 2 is a cross-sectional view taken along the line XX ′ of FIG. 1, in which the first electrode 2, the insulating layer 4, and the thin film layer 1 are formed on the substrate 1.
0, the second electrode 8 is laminated.

In FIG. 1, the light-emissible region is a region where the first electrode and the second electrode intersect with each other and corresponds to the opening of the insulating layer. When the first electrode and the second electrode are orthogonal to each other, the area of the light-emissible region can be estimated from the line width of the first electrode and the line width of the second electrode. Since the insulating layer is formed so as to cover the portion, it is often slightly smaller than the area of the portion where the first electrode and the second electrode overlap. The organic electroluminescent device of the present invention is characterized in that the area capable of emitting light is 1 mm 2 or less, and in many cases the area is 0.1 mm 2 or less.

The area of the light-emissible region is 1 mm 2 when the device has a line width of the first electrode and the second electrode of about 1 mm. In the case of a high-definition color display, the first electrode has a line width of 75 μm and a pitch of 10 μm.
The second electrode has a line width of 250 μm and a width of 300 μm.
In the example of being formed with the μm pitch, the area of the light emitting region is 0.01875 square millimeters.

The organic electroluminescent device of the present invention has an insulating layer formed so as to cover a part of the first electrode. This insulating layer can have a function of preventing a short circuit between the first electrode and the second electrode and protecting the edge portion of the first electrode. As the material of the insulating layer, various inorganic and organic materials are used. Examples of the inorganic material include silicon oxide and other oxide materials such as manganese oxide, vanadium oxide, titanium oxide, and chromium oxide, silicon, and gallium. Semiconductor materials such as arsenic, glass materials, ceramic materials, and the like, and organic materials include polyvinyl, polyimide, polystyrene, novolac, and silicone polymer materials. Various known forming methods can be applied to the formation of the insulating layer. A photolithography method using a photosensitive resin is a preferable forming method, and the photosensitive resin is preferably a positive type which is easy to obtain a tapered shape. In particular, it is preferable to form the insulating layer using a positive photosensitive polyimide having excellent reliability.

The thickness of the insulating layer formed by the present invention is 0.1 μm.
It is preferably m or more. The insulating layer of inorganic material is
Patterning can be performed using an etching method or a lift-off method, but the thickness is preferably 0.1 μm or more. When an organic material such as a photoresist is used, it can be installed to a thickness of 1 μm or more, and thus the thickness exceeds the thickness of a thin film layer including at least a light emitting layer made of an organic compound. By setting
When patterning using a shadow mask, the insulating layer can also be used as a spacer that prevents mask scratches.

In order to manufacture the organic electroluminescent device of the present invention, an ITO substrate having a transparent film of indium tin oxide (ITO) formed on the surface of a glass substrate by a sputtering method or the like is patterned by photolithography to form a stripe-shaped first substrate. A method of forming one electrode and then forming an insulating layer is used. As described above, a general photolithography method or a combination of a photolithography method and a vacuum deposition method is used for forming the insulating layer. Thereafter, a thin film layer including at least a light emitting layer made of an organic compound is formed, and a second electrode is formed to obtain an organic electroluminescence device. The manufacturing method of the present invention is characterized in that an insulating layer is formed before the thin film layer is formed. Is being dehydrated.

[0020] That is, you dehydrated insulating layer by heating the substrate to 80 ° C. or higher before the thin film layer formation. Or the substrate you dehydrated insulation layer by placing it in the reduced pressure atmosphere. The dehydration treatment by heating and the dehydration treatment under a reduced pressure atmosphere may be performed individually, but it is also effective to perform each treatment continuously or simultaneously. Also, the order is not particularly limited. The total time of placing under vacuum atmosphere until the formation of the thin film layer is Ru <br/> Ah at 10 minutes or more. Also, rather than increasing the degree of pressure reduction and processing in a short time,
It is preferable to prolong the holding time in the reduced pressure atmosphere. Holding in a reduced pressure atmosphere for at least 10 minutes or longer, preferably 20 minutes or longer is effective for the dehydration treatment of the insulating layer, and the effect of increasing the effective light emission rate can be exhibited. When the thin film layer of the organic electroluminescence device is manufactured by a vacuum vapor deposition method or the like, dehydration treatment can be performed at the same time during evacuation.

After the insulating layer is formed using an inorganic or organic material, the substrate is heated at a temperature of 80 ° C. or higher, or after the post-treatment associated with this formation, the substrate is heated in a reduced pressure atmosphere for a total time of 1 hour.
The effective emission rate of the obtained organic electroluminescence device can be improved to 80% or more by allowing the treatment of leaving for 0 minutes or more to pass or by performing the treatment in which both are combined.

After performing the insulating layer formation and the above-mentioned dehydration treatment,
If necessary, a spacer having a height at least a part of which exceeds the thickness of the thin film layer is formed, and then a thin film layer including a light emitting layer is formed on the first electrode. The structure of the thin film layer,
1) hole-transporting layer / light-emitting layer, 2) hole-transporting layer / light-emitting layer / electron-transporting layer, 3) light-emitting layer / electron-transporting layer, and 4) light-emitting layer in a form in which the above layer-constituting substances are mixed in one layer. Etc., but any of them may be used. Hole transport layer, light emitting layer,
Known materials are used for the organic layers such as the electron transport layer.
Various deposition methods using a shadow mask can be applied to pattern formation of these thin film layers. The dehydration treatment of the present invention is also effective for a polymer organic electroluminescent device in which a light emitting layer is formed by a spin coating method, an inkjet coating method, or the like.

After that, the second electrode material is vapor-deposited by the partition wall method or the mask vapor deposition method to form the stripe-shaped second electrode, whereby the target organic electroluminescence device can be obtained.
Further, after forming the second electrode, a protective film may be formed or sealing may be performed by a known technique.

[0024]

The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

Example 1 An ITO glass substrate (manufactured by Geomatec Co., Ltd.) in which an ITO transparent electrode film having a thickness of 130 nm was formed on a 1.1 mm-thick non-alkali glass surface by a sputtering deposition method was used.
It was cut into a size of 20 × 100 mm. A photoresist was applied on the ITO substrate, and patterning was performed by exposure and development using a normal photolithography method. ITO
After removing the unnecessary part of the film by etching, the photoresist is removed to make the ITO film 90 mm long and 80 mm wide.
It was patterned into a stripe shape of μm. 816 stripe-shaped first electrodes are arranged at a pitch of 100 μm.

Next, a positive photoresist (OFPR-800 manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied by spin coating to a thickness of 3 μm on the substrate on which the first electrode was formed. This coating film was pattern-exposed through a photomask, developed to pattern the photoresist, and cured at 160 ° C. after development. This insulating layer has a width of 65μ
Openings having a length of m and a length of 235 μm are arranged in the width direction at 816 pitches of 100 μm and in the length direction at 200 pitches of 300 μm. The insulating layer covers the end portion of the first electrode, and the central portion of the first electrode is exposed from the opening.

The substrate having the insulating layer thus formed was transferred to a vacuum dryer in dry air and placed in a vacuum atmosphere at room temperature and 10 Pa for 10 minutes for dehydration treatment.

The thin film layer including the light emitting layer was formed by a vacuum vapor deposition method using a resistance wire heating method. The degree of vacuum during vapor deposition was 2 × 10 ⁻⁴ Pa or less, and the substrate was rotated with respect to the vapor deposition source during vapor deposition. First, in the arrangement as shown in FIG. 3, copper phthalocyanine having a thickness of 15 nm and bis (N-ethylcarbazole) having a thickness of 60 nm were vapor-deposited on the entire surface of the substrate to form the hole transport layer 5.

For patterning the light emitting layer, a shadow mask having a mask portion and a reinforcing line formed in the same plane as shown in FIG. 4 was used. Shadow mask outline is 1
20 × 84 mm, the mask portion 31 has a thickness of 25 μm, and 272 stripe-shaped openings 32 having a length of 64 mm and a width of 100 μm are arranged at a pitch of 300 μm. Each stripe-shaped opening has a width of 20 μ perpendicular to the opening.
Reinforcing wires 33 having a thickness of m and a thickness of 25 μm are formed at intervals of 1.8 mm. The shadow mask is fixed to a stainless steel frame 34 having a uniform width and a width of 4 mm.

A shadow mask for the light emitting layer was placed in front of the substrate to bring them into close contact with each other, and a ferrite plate magnet (YBM-1B, manufactured by Hitachi Metals, Ltd.) was placed behind the substrate. On this occasion,
As shown in FIGS. 5 and 6, the stripe-shaped first electrode 2 is located at the center of the stripe-shaped opening 32 of the shadow mask, the reinforcing wire 33 is located on the insulating layer, and the reinforcing wire and the insulating layer are Arranged to touch. 0.3 in this state
Wt% 1,3,5,7,8-pentamethyl-4,4-
Difluoro-4-bora -3a, 4a-diaza -s- indacene (PM546) doped with 8-hydroxyquinoline - aluminum complex (Alq ₃₎ was 21nm deposited and patterned green emission layer.

Next, the shadow mask is aligned with the first electrode pattern at a position shifted by one pitch, and the shadow mask is adjusted to 1% by weight.
Alq ₃ doped with 4- (dicyanomethylene) -2-methyl-6- (julolidylstyryl) pyran (DCJT) of 15 nm was vapor-deposited with a thickness of 15 nm to pattern the red light emitting layer.

Further, the shadow mask is aligned with the first electrode pattern at a position shifted by one pitch, and 4, 4 '
-Bis (2,2'-diphenylvinyl) diphenyl (D
PVBi) was evaporated to a thickness of 20 nm to pattern the blue light emitting layer. The green, red, and blue light emitting layers are arranged for every three stripe-shaped first electrodes, and completely cover the exposed portions of the first electrodes.

Next, in the arrangement shown in FIG. 7, DPVB
i was 35 nm and Alq ₃ was 10 nm on the entire surface of the substrate. After that, the thin film layer was exposed to lithium vapor for doping (film thickness conversion amount 0.5 nm).

For patterning the second electrode, a shadow mask having a structure in which a gap 36 exists between one surface 35 of the mask portion 31 and the reinforcing line 33 as shown in FIGS. 8 and 9 was used. The outer shape of the shadow mask is 120 x 84 m
m, the thickness of the mask portion is 100 μm, and the length is 100
200 stripe-shaped openings 32 having a width of 250 mm and a width of 250 μm are arranged at a pitch of 300 μm. On the mask portion, a mesh-like reinforcing wire having a regular hexagonal structure having a width of 40 μm, a thickness of 35 μm, and an interval between opposite two sides of 200 μm is formed. The height of the gap is 100 μm, which is equal to the thickness of the mask portion. The shadow mask is fixed to a stainless steel frame 34 having a uniform width and a width of 4 mm.

The second electrode was formed by a vacuum evaporation method using a resistance wire heating method. The degree of vacuum during vapor deposition is 3 × 1.
The ^{pressure was} 0 ⁻⁴ Pa or less, and the substrate was rotated with respect to two vapor deposition sources during vapor deposition. Similar to the patterning of the light emitting layer, a shadow mask for the second electrode was placed in front of the substrate to bring them into close contact with each other, and a magnet was placed behind the substrate. At this time, as shown in FIGS. 10 and 11, both of them are arranged so that the insulating layer coincides with the position of the mask portion 31. In this state, aluminum was vapor-deposited to a thickness of 400 nm to pattern the second electrode 8. The second electrode is arranged orthogonally to the first electrodes that are patterned in a plurality of stripes arranged at intervals, and is patterned in a stripe shape arranged at intervals.

Thus, the width is 70 μm and the pitch is 100.
A patterned green light emitting layer, a red light emitting layer, and a blue light emitting layer are formed on the ITO stripe-shaped first electrode of μm and the number of which is 816, and the width is 2 so as to be orthogonal to the first electrode.
A simple matrix type color organic electroluminescence device in which 200 stripe-shaped second electrodes having a pitch of 50 μm and a pitch of 300 μm were arranged was produced. Since the three light emitting regions of red, green, and blue form one pixel, the present light emitting device has two pitches of 300 μm.
It has 72 × 200 pixels. The light emitting area of one light emitting pixel is regulated by the opening of the insulating layer, so the width is 65 μm.
And the length is 235 μm, and the area of the light-emissive region is 0.0
It is 15275 square millimeters.

The apparatus was taken out of the vapor deposition machine, kept under a reduced pressure atmosphere by a rotary pump for 20 minutes, and then transferred to an argon atmosphere having a dew point of -100 ° C or lower. In this low-humidity atmosphere, the substrate and the glass plate for sealing were bonded together by using a curable epoxy resin for sealing.

Immediately after manufacturing the organic electroluminescent device, the effective light emission rate is 100% in many parts and 90% in the lowest part. Since the variation in the effective light emission rate of each pixel is small, the line sequential driving method is used. Good display characteristics with less uneven brightness were obtained. Further, the effective light emission rate was higher than 85% even after 3 months.

Example 2 The same as Example 1 except that the substrate on which the insulating layer was formed was transferred to a vacuum dryer in dry air and placed under a reduced pressure atmosphere of room temperature and 10 Pa for 20 minutes for dehydration treatment. Then, an organic electroluminescence device was produced. The effective light emission rate immediately after fabrication was 100% in many parts and 96% in the lowest part. Since the variation in the effective light emission rate of each pixel was small, the brightness unevenness was better than that of Example 1 and good. Display characteristics were obtained. In addition, no change was observed in the effective luminescence rate after one month. No significant change was observed in the effective emission rate even after 3 months.

Example 3 The substrate on which the insulating layer was formed was transferred to a vacuum drier in dry air, heated to 80 ° C., and then placed in a depressurized atmosphere of 10 Pa for 30 minutes for dehydration treatment. An organic electroluminescence device was produced in the same manner as in Example 1. Immediately after fabrication, the effective light emission rate is 100% in most parts and 9 even in the lowest parts.
Since it was 8%, and the variation in the effective light emission rate of each pixel was small, good display characteristics with less luminance unevenness were obtained compared to Example 2. In addition, no change was observed in the effective luminescence rate after one month. No significant change was observed in the effective emission rate even after 3 months.

Comparative Example 1 An organic electroluminescence device was produced in the same manner as in Example 1 except that the substrate having the insulating layer was not dehydrated. The effective light emission rate was less than 80% in many parts immediately after the production, and the variation in the effective light emission rate of each pixel was large, so that only display characteristics with conspicuous luminance unevenness were obtained. Further, the effective luminescence rate decreased to less than 70% after 1 day. This means that a large current density is required to obtain the same brightness as that of the embodiment, and the load on the element is increased as compared with the embodiment. Further, the diffusion of water from the insulating layer to the thin film layer causes the number of pixels that are short-circuited and become non-luminous to increase with time, which further deteriorates the display characteristics.

Example 4 The first electrode was patterned in the same manner as in Example 1. Next, a positive photosensitive polyimide precursor (Toray Industries, Inc.)
Manufactured by PW-1000), the concentration was adjusted, the solution was applied onto the substrate on which the first electrode was formed by spin coating, and prebaked on a hot plate at 120 ° C. for 2 minutes. After this film was exposed to UV through a photomask, 2.38% TM
Develop by dissolving only the exposed part with AH aqueous solution,
Rinse with pure water. The obtained polyimide precursor pattern was heated at 170 ° C. for 30 minutes in a nitrogen atmosphere in a clean oven.
Minute, and further, cured by heating at 320 ° C. for 60 minutes. The polyimide insulating layer has a width of 65 μm and a length of 23
5 μm openings are 816 at 100 μm pitch in width direction
200 pieces are arranged at a pitch of 300 μm in the length direction. The insulating layer covers the end portion of the first electrode, and the central portion of the first electrode is exposed from the opening. It was confirmed that the thickness of the insulating layer was about 4 μm and the volume resistivity was at least 10 ⁸ Ωcm. The cross section of the boundary portion of the insulating layer had a forward tapered shape, and the taper angle was about 45 °.

The dehydration treatment was carried out in the same manner as in Example 3. The thin film layer and the second electrode were formed and sealed in the same manner as in Example 1.

The effective light emission rate of the obtained organic electroluminescence device immediately after fabrication was 100% in most parts and 96% in the lowest part, and the variation in the effective light emission rate of each pixel was small, resulting in uneven brightness. A few good display characteristics were obtained.
In addition, no change was observed in the effective luminescence rate after one month. No significant change was observed in the effective emission rate even after 3 months.

Example 5 The first electrode was patterned in the same manner as in Example 1. Next, a negative type lift-off photoresist (ZPN1100 manufactured by Zeon Corporation) is applied to a thickness of 3 μm on the entire surface.
m. The photomask used for patterning this resist has openings of 65 μm width and 235 μm length with a pitch of 100 μm in the width direction and 300 μm in the length direction.
Those arranged at a pitch were used. The patterning was performed by aligning the photomask with a width of 65 μm on the stripe-shaped first electrode in the center thereof.

The feature of this lift-off resist is that it has a reverse taper shape. Subsequently, a silicon oxide film having a thickness of 150 nm was formed on the entire surface of the glass substrate by the electron beam evaporation method. When this substrate is ultrasonically cleaned in acetone, the lift-off resist is dissolved, and the silicon oxide film deposited on the opening of the resist remains on the first electrode. That is, the insulating film has a width of 65 μm that matches the pattern arrangement of the photomask used for patterning the lift-off resist.
235 μm long opening with 100 μm in width direction
The pitch is 300 μm in the length direction. That is, the insulating layer is formed on the substrate excluding these openings.

A polyimide-based photosensitive coating agent (manufactured by Toray Industries, Inc., UR) on the substrate on which the first electrode and the insulating layer are formed.
-3100) by spin coating in a clean oven,
Prebaking was performed at 80 ° C. for 1 hour in a nitrogen atmosphere. Next, this coating film was pattern-exposed through a photomask and then developed using a developer (Toray Industries, Inc., DV-505). Thereafter, baking was performed in a clean oven at 180 ° C. for 30 minutes, and further at 220 ° C. for 30 minutes to form partition walls orthogonal to the first electrode. The semi-transparent and electrically insulating partition is located on the insulating layer and has a length of 104 m.
m, width 50 μm, height 4 μm, and 201 pieces are arranged at a pitch of 300 μm.

The dehydration treatment was carried out in the same manner as in Example 3. The thin film layer was formed in the same manner as in Example 1. The partition method was used for forming the second electrode. That is, oblique deposition is performed in a state where the substrate is installed at an angle with respect to the deposition source, and
m aluminum was deposited. Example 1 for sealing
I went the same way.

Immediately after manufacturing the obtained organic electroluminescent device, the effective light emission rate was 100% in most parts and 98% in the lowest part. Since the variation in the effective light emission rate of each pixel was small, uneven brightness was caused. A few good display characteristics were obtained.
In addition, no change was observed in the effective luminescence rate after one month. No significant change was observed in the effective emission rate even after 3 months.

Example 6 ITO was patterned in the same manner as in Example 1 to give a length of 9
272 stripe-shaped first electrodes having a width of 0 mm, a width of 270 μm, and a pitch of 300 μm were formed.

Next, the insulating layer was patterned in the same manner as in Example 1 to arrange 272 opening portions having a width of 265 μm and a length of 750 μm at a pitch of 300 μm in the width direction and at a pitch of 900 μm in the length direction. Has been done. The dehydration treatment was performed in the same manner as in Example 3, and the hole transport layer was formed in the same manner as in Example 1.

For patterning the light emitting layer, a shadow mask having a structure in which a mask portion and a reinforcing line were formed in the same plane as shown in FIG. 4 was prepared. The outer shape of the shadow mask is 120 × 84 mm, and the thickness of the mask portion 31 is 25.
92 stripes 32 having a length of 64 mm and a width of 305 μm are arranged laterally at a pitch of 900 μm. In each stripe-shaped opening, a reinforcing wire 33 having a width of 20 μm and a thickness of 25 μm orthogonal to the opening is 1.8 m.
It is formed every m. Further, the shadow mask is fixed to a stainless steel frame 34 having a uniform width and a width of 4 mm. Using this mask, the light emitting layer was patterned in the same manner as in Example 1.

The vapor deposition of DPVBi and Alq ₃ and the doping of Li were performed in the same manner as in Example 1.

For patterning the second electrode, a shadow mask having a structure in which a gap 36 exists between one surface 35 of the mask portion 31 and the reinforcing line 33 as shown in FIGS. 8 and 9 was prepared. The external shape of the shadow mask is 120 × 84
mm, the thickness of the mask portion is 170 μm, and the length is 10
Sixty stripe-shaped openings 32 having a width of 0 mm and a width of 770 μm are arranged laterally at a pitch of 900 μm. On the mask portion, a mesh-like reinforcing wire having a regular hexagonal structure having a width of 45 μm, a thickness of 40 μm, and an interval between opposite two sides of 200 μm is formed. The height of the gap is 170 μm, which is equal to the thickness of the mask portion. In addition, the shadow mask is made of a stainless steel frame 3 with a uniform width of 4 mm.
It is fixed at 4. Using this mask, the second electrode was patterned in the same manner as in Example 1.

Thus, the width is 270 μm and the pitch is 30.
A patterned green light-emitting layer, a red light-emitting layer and a blue light-emitting layer are formed on an ITO stripe-shaped first electrode having a thickness of 0 μm and a number of 272, and a width 7 is formed so as to be orthogonal to the first electrode.
A simple matrix type color organic electroluminescent device in which 66 stripe-shaped second electrodes having a pitch of 70 μm and a pitch of 900 μm were arranged was produced. Since the three light emitting regions of red, green, and blue form one pixel, this light emitting device has 90
It has × 66 pixels. Since the light-emissible area of one light-emission pixel is regulated by the opening of the insulating layer, it has a width of 265 μm and a length of 750 μm, and the area of the light-emissible area is 0.198.
It is 75 square millimeters. Example 1 for sealing
I went the same way.

Immediately after the production of this organic electroluminescent device, the effective light emission rate is 100% in many parts and 99% in the lowest part. Since the variation in the effective light emission rate of each pixel is small, the line sequential driving method is used. Good display characteristics with less uneven brightness were obtained. In addition, no change was observed in the effective luminescence rate after one month. No significant change was observed in the effective emission rate even after 3 months.

[0057]

EFFECTS OF THE INVENTION By setting the effective light emission rate, which represents the area of the region that actually emits light, in the light emitting region of the pixel to 80% or more, good display characteristics with less uneven brightness can be obtained. Further, the load on the organic electroluminescent device is reduced, and the short circuit of the pixel can be suppressed. If the effective light emission rate is 85% or more after 1 month, and further after 3 months,
There is no significant decrease in the effective light emission rate thereafter, and stable display characteristics can be expected over a long period of time. Such an organic electroluminescence device can be obtained by heat-treating the substrate at a temperature of 80 ° C. or higher after forming the insulating layer, or by performing a dehydration treatment of leaving the substrate in a reduced pressure atmosphere for 10 minutes or more.

[Brief description of drawings]

FIG. 1 is a plan view illustrating a light emitting area and an actual light emitting area.

FIG. 2 is a sectional view taken along line XX ′ of FIG.

FIG. 3 is an XX ′ illustrating an example of a method for forming a hole transport layer.
Sectional view.

FIG. 4 is a plan view showing an example of a shadow mask for patterning a light emitting layer.

FIG. 5 illustrates an example X of a method for patterning a light emitting layer.
X'sectional view.

FIG. 6 illustrates an example of a light emitting layer patterning method Y
Y'sectional view.

FIG. 7 is XX ′ illustrating an example of a method for forming an electron transport layer.
Sectional view.

FIG. 8 is a plan view showing an example of a shadow mask for patterning a second electrode.

FIG. 9 is a sectional view showing an example of a shadow mask for patterning a second electrode.

FIG. 10 illustrates an example X of patterning the second electrode.
X'sectional view.

FIG. 11 is a diagram Y illustrating an example of second electrode patterning.
Y'sectional view.

[Explanation of symbols]

1 substrate 2 First electrode 4 insulating layers 5 Hole transport layer 6 light emitting layer 7 Electron transport layer 8 Second electrode 10 thin film layers 11 Hole transport materials 12 Luminescent material 13 Electronic transport materials 14 Second electrode material 15 Light emitting area 16 Real light emission area 30 shadow mask 31 Mask part 32 openings 33 Reinforcement line 34 frames 35 One side of mask part 36 gap

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05B 33/12 H05B 33/12 B 33/14 33/14 A (56) References JP 2000-150147 (JP, A) Special features Open 2000-30871 (JP, A) JP 2000-21579 (JP, A) JP 2001-110573 (JP, A) JP 2002-62422 (JP, A) JP 2001-126862 (JP, A) International Publication 01/072091 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) H05B 33/00-33/28

Claims (5)

(57) [Claims] 1. A first electrode formed on a substrate, an insulating layer formed so as to cover a part of the first electrode, and a light emitting layer made of at least an organic compound formed on the first electrode. An organic electroluminescent device including a thin film layer and a second electrode formed on the thin film layer, wherein an area of a light-emissible region defined by the first electrode, the insulating layer, and the second electrode is
It is less than 1 mm2, and the substrate is
Dehydrating the insulating layer by heating it to 80 ℃ or higher
Accordingly, with respect to the area of the light emitting area, actually organic electroluminescent device, characterized in that the effective light emitting ratio defined in 80% or more as a ratio of the area of the actual emission region emits light. 2. A first electrode formed on a substrate, an insulating layer formed so as to cover a part of the first electrode, and a light emitting layer made of at least an organic compound formed on the first electrode. An organic electroluminescent device including a thin film layer and a second electrode formed on the thin film layer, wherein an area of a light-emissible region defined by the first electrode, the insulating layer, and the second electrode is
It is less than 1 mm2, and the substrate is
Dehydrate the insulation layer by leaving it in a reduced pressure atmosphere for 10 minutes or more.
By doing so, the effective electroluminescence rate defined as the ratio of the area of the actual light-emitting area that actually emits light to the area of the light-emissive area is set to 80% or more. 3. The organic electroluminescent device according to claim 1 or 2, wherein the area of the light-emitting region is not more than 0.1 mm 2. 4. A heat treatment for forming an insulating layer is performed,
Further, the organic electroluminescence device of claim 1 or 3, wherein the dehydrating process the insulating layer by heating the substrate to 80 ° C. or higher. 5. The insulating layer is made of a positive photosensitive material.
Organic electroluminescence according to any one of claims 1 to 4, characterized in that
apparatus.